Introduction: Failed Car Alternator Work Around

Picture of Failed Car Alternator Work Around

Failed Car Alternator Quick Work Around

So you car's alternator has failed and you have no time to get it fixed... Your battery under the hood may even be dead from running your car without a functioning alternator. You need to drive your car NOW!.... What to do?

My solution was to add a second battery in the passenger compartment that could be easily charged or swapped out to keep the car going and get you to your destination. You don't have to wait to charge the dead battery and you don't have to swap out the battery under the hood.

Add a second battery on the passenger floorboard. You get twice the capacity with both batteries charged. Remember your car electrical system is running only on battery and is not being recharged by the alternator -- ultimately the batter(ies) will be exhausted and your car will not drive, so having more battery capacity is a good thing.

This quick 'fix' gets you up and driving as fast as possible with minimal work on the car.

CAUTION / DISCLAIMER: Although I have used the method described to drive a car with a broken alternator, I do not recommend it. This Instructable is mainly for entertainment purposes. There are many hazards that can be introduced and many that may be unforeseen. So don't do it. If you do, you are responsible for your actions and not me. In other words, I don't want to hear from your lawyer! Be safe and smart.

Step 1: Materials

Picture of Materials

Materials:

1. Second Automotive Battery (Fully Charged - You keep it charged all the time just in case, don't you?)

2. Long Heavy Duty Jumper Cables

3. The All Important Duct Tape

Step 2: Position Your 'Secondary' Battery on the Passenger Floorboard

Picture of Position Your 'Secondary' Battery on the Passenger Floorboard

Place the second battery on the passenger floorboard, making sure it is level and stable. You don't want it falling over and spilling electrolyte (sulfuric acid).

Step 3: Run the Jumper Cables Through the Window

Picture of Run the Jumper Cables Through the Window

Open the passenger's window and run the jumper cables through the window.

Make sure the jumper cables are not shorted together. You can do this by clamping one of the jaws onto the insulated cable so they don't touch. Only do this if the teeth on the jaw will not damage the insulation on the cables.

Step 4: Open the Hood and Run the Jumper Cables to the Battery

Picture of Open the Hood and Run the Jumper Cables to the Battery

Snake your jumper cables across the engine compartment to the existing car battery. Make sure that the jumper cables will not get caught in any moving parts, especially belts or fans. Make sure the cable insulation will not contact hot parts and melt. Make sure the cables will not bounce around and get caught in moving parts or contact hot parts. You might have to use some duct tape here.

Step 5: Connect the Jumper Cables to the Car Battery

Picture of Connect the Jumper Cables to the Car Battery

Connect the jumper cables coming from the passenger compartment battery (not connected) to the car's battery under the hood. Position the jumper cable clamps/jaws to that they can lay as flat as possible so that the hood could be closed. Make sure that the clamps don't short against each other or the opposite battery post or to the car frame or other metal.

Step 6: Gently Close the Car Hood Until the Safety Catch Engages

Picture of Gently Close the Car Hood Until the Safety Catch Engages

With the jumper cables positioned as near to the front of the hood as possible, gently close the car hood making sure that nothing shorts out and nothing gets pinched. You won't be able to close the hood all the way because of the jumper cables leaving the engine compartment. But gently close the hood until the Hood Safely Catch Latches onto the hood.

Reposition the jumper cables if necessary to get the hood to close enough to engage the Safety Catch. This catch keeps the hood from flying off in case it was not closed properly or the main latch fails. In this case the Hood Safety Catch keeps the hood closed while driving.

If you're Hood Safety Catch is not there, is damaged, or doesn't function properly don't use this Instructable.

Step 7: Tape Down the Jumper Cables

Picture of Tape Down the Jumper Cables

Duct Tape the Jumper Cables in place from the engine compartment back the the passenger compartment.

Carefully roll up the passenger window so that the window is as closed as it can be without pinching the jumper cables too much.

Step 8: Connect the Interior Battery

Picture of Connect the Interior Battery

Connect the Jumper Cables to the passenger compartment battery.

Your are good to drive off to your destination!

Enjoy!

Comments

Mipela (author)2017-09-04

Good suggestion for short period, with extra Battery it will encourage the repair of alternator.

dadsaid5x (author)2017-08-28

I SURE HOPE YOU DONT GET INVOLVED IN A COLLISION WITH OH, I DONT KNOW, MAYBE A GALLON OF ACID JUST FEET AWAY FROM YOUR FACE, YOUR JUNK, YOU!

wannabemadsci (author)dadsaid5x2017-08-29

Valid Point - As I said:

"CAUTION / DISCLAIMER: Although I have used the method described to drive a car with a broken alternator, I do not recommend it. This Instructable is mainly for entertainment purposes. There are many hazards that can be introduced and many that may be unforeseen. So don't do it. If you do, you are responsible for your actions and not me. In other words, I don't want to hear from your lawyer! Be safe and smart."

bbqandbeer (author)wannabemadsci2017-08-29

The dead battery serves no purpose, its smarter to swap out the dead with a charged one. if you have 2 charged batteries, id keep one in the trunk and swap accordingly. Also your setup is running in parralel, not series that would actually benefit you.

wannabemadsci (author)bbqandbeer2017-08-31

Thanks for the comment. My intent was to avoid doing any work on the car. Getting a battery out of the engine compartment can be a bit time consuming particularly if the battery clamp is rusted.

I am not sure I understand your comment to connect the batteries in series - my car would not like 24V ! :-)

PhillipS1 (author)wannabemadsci2017-08-31

Even a rusted clamp can't be more time consuming than rigging cables to a second battery inside the car. Also, most people don't just have a second battery lying around. If a person isn't comfortable enough to remove a serpentine belt and unbolt an alternator, they're probably not going to be comfortable running jumper cables inside the passenger compartment to a completely unsecured battery on the floor.

PhillipS1 (author)bbqandbeer2017-08-31

series would double the voltage, that's not a good idea.

Jph37 (author)2017-08-29

I have done something similar when my alternator went out on a Wednesday and I wouldn't have time to change it until Saturday. I bought a cheap trickle charger at Walmart and mounted it under the hood, connected the leads to the battery terminals, and ran the plug a short way out from the front grill. Charged the battery overnight and would have a full charge for the morning drive to work. Carry along an extension cord and charge it at work so I could get home. Worked great for a few days and didn't kill the battery. I also didn't use any "extra" electrical i.e. Lights, ac, fans, radio, etc so I could get the most life out of the charge for those few days.

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